Light-emitting diodes are analog devices in that their output, i.e., the brightness or the luminous intensity of the emitted light, is dependent on the analog value of the input current. A variation of this operation mode is to use a fixed value of the forward current, i.e., a constant current value, and then to vary the duration of the forward current by pulse-width modulation (PWM) to change the duty cycle which is proportional to the LED output.
Typical light-emitting diodes delivered to video display makers are selected light-emitting diodes with a floating single bin in brightness with a combined single wavelength group. These pre-sorted light-emitting diodes are often inadequate to provide the necessary homogeneity in color and brightness. The brightness bin is usually between 30% and 60% wide, the wavelength bin is usually between 4 nm and 5 nm wide.
It could therefore be helpful to provide a light-emitting diode which has a predetermined luminous intensity at a predetermined emission wavelength and a method of producing such a light-emitting diode.